What does the word photography mean? Well, quite literally "light graphics". Light striking film - um er nowdays a sensor is recorded. What can help to make a really great photograph? One of the most essential elements is light.
Take the hay bales in the field in my Michigan Gallery. Taken at midday, colors would have been less saturated. Why? Midday sun shines a lot of UV light on a subject. UV light tends to be very reflective and thus much of the color is lost to glare. Also, this bright light produces harsh shadows and contrasting brightness. The hay bales photo taken just before sunset meant that the sun was at a low angle and passed through more of the earth's atmosphere. This filtered the UV light producing a softer more pleasant light and greater color saturation.
Next "The Characteristics of Light"